Friend's girlfriend Lisa Ann fucking in the couch

It's a special girlfriend-swapping night; Lisa Ann and her boyfriend are going out with another pair. She has never gone swinging or done anything similar, so she's worried, but the two couples have always spoken about it. When she gets to her buddy Mark's house early for their date, she discovers that both of their other halves are late from work. Lisa pulls out her enormous tits and sits on his enormous erect cock as they decide to give their night a go!